ORIGINAL ARTICLE Pneumothorax and Pneumomediastinum with Subcutaneous Emphysema Following Parathyroidectomy and Thyroidectomy Russel Krawitz1​, Anthony Glover2​, Ahmad Aniss3​, Mark Sywak4​, Leigh Delbridge5​, Stan Sidhu6

Abstract Background: Thyroidectomy and parathyroidectomy have become safe procedures with low postoperative morbidity and complication rates—hypocalcemia, RLN injury and postoperative hematoma being the most common. In our institution the risk of hematoma following sutureless technique is 1%.1 ​Pneumothorax following thyroidectomy and parathyroidectomy has only been reported a few times in the literature without a clear etiology. Materials and methods: Retrospective review of the complication database of the Royal North Shore Endocrine Surgical Unit from 2000 to 2018. Results: Three cases of pneumothorax or pneumomediastinum were found following thyroidectomy or parathyroidectomy with an incidence of 0.02%. A recent case of pneumomediastinum and subcutaneous emphysema following an open parathyroidectomy was attributed to the Valsalva maneuver at the end of the case. Two further cases of pneumothorax at our institution occurred post parathyroidectomy. In both cases, a laryngeal mask was used and Valsalva maneuver (VM) was not performed. All cases were managed conservatively and made a full recovery. Conclusion: The combination of pneumomediastinum with subcutaneous emphysema in the most recent case is likely from a ruptured bulla secondary to Valsalva maneuver or lung injury during mediastinal dissection. This likely caused an air leak with gas tracking up into the neck from the mediastinum. The probable etiology in the other two cases is a negative mediastinal pressure created from laryngospasm with an open neck wound and dissection in the inferior neck and superior mediastinum. Keywords: Parathyroid, Parathyroidectomy, Pneumomediastinum, Pneumothorax, Subcutaneous emphysema, Thyroidectomy, Valsalva maneuver. World Journal of Endocrine Surgery (2019): 10.5005/jp-journals-10002-1259

Introduction 1–6​University of Sydney Endocrine Surgical Unit, Royal North Thyroidectomy and parathyroidectomy have become safe Shore Hospital, Northern Sydney Local Health District, Sydney, procedures with low postoperative morbidity and complication Australia rates, hypocalcemia and RLN injury being the most common. Post- Corresponding Author: Russel Krawitz, University of Sydney operative bleeding leading to cervical hematoma is an extremely Endocrine Surgical Unit, Royal North Shore Hospital, Northern serious complication of thyroidectomy with potential respiratory Sydney Local Health District, Sydney, Australia, Phone: +61 447022315, arrest from airway compromise. In our institution the risk of e-mail: [email protected] hematoma following sutureless technique is 1%.1​ How to cite this article: Krawitz R, Glover A, et al. ​Pneumothorax and Many strategies are used to prevent postoperative hematoma Pneumomediastinum with Subcutaneous Emphysema Following with meticulous hemostasis at the end of the procedure being Parathyroidectomy and Thyroidectomy. World J Endoc Surg paramount. Valsalva maneuver (VM) is a common technique used 2019;11(2):46–48. prior to wound closure to detect occult bleeding and prevent post- Source of support:​ Nil operative hematoma. Conflict of interest:​ None Valsalva maneuver causes a number of complex physiological changes, but in the operative setting for neck surgery, the most important effect is the increased venous pressure within the jugular Materials and Methods veins as a result of decreased venous return from the elevated The study group included all patients having thyroidectomy or intrathoracic pressure.2​ By increasing venous pressure occult parathyroidectomy that were treated by the University of Sydney bleeding sites will become evident for the surgeon to then control Endocrine Surgical Unit based at Royal North Shore Hospital, Sydney by any number of surgical techniques. between 2000 and 2018. Data were stored in a dedicated endocrine Valsalva maneuver is generally a safe procedure but there are surgical database and was audited on a monthly basis. reports in the literature of complications resulting from barotrauma. Included in this study were patients who had a pneumothorax These include neurological injury such as stroke, VM induced or pneumomediastinum as a complication of thyroid or parathyroid retinopathy, pneumothorax and pneumomediastinum as a result surgery. of alveolar or bullous rupture.2​ A recent case of pneumomediastinum and subcutaneous emphysema following an open parathyroidectomy, was attributed Results to the VM at the end of the case, but this series will report two further Between 2000 and 2018 a total of 15,000 thyroidectomies and cases of pneumothorax which occurred post parathyroidectomy parathyroidectomies were performed. During this period, three both in which VM was not performed. patients had a recorded pneumothorax or pneumomediastinum as

© The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons. org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Pneumothorax and Pneumomediastinum with Subcutaneous Emphysema a complication of surgery, giving this complication an incidence of descended right parathyroid adenoma found in the trachea- 0.02%. All three patients had parathyroidectomy and in one case a esophageal groove below the lower pole of the right thyroid combined parathyroidectomy and thyroidectomy was performed. lobe. After removal of the adenoma PTH levels fell appropriately. All three patients were managed conservatively without need Postoperatively she experienced chest pain and was found to have for an intercostal catheter and all made a full recovery. Details of an apical pneumothorax on CXR. This was managed conservatively the individual cases are presented. and patient recovered fully. A laryngeal mask was used during surgery and no VM was Patient 1 performed during the operation. A 66-year-old female with primary hyperparathyroidism and multinodular goiter who underwent a 4-gland exploration with Patient 3 right inferior parathyroidectomy and right hemithyroidectomy in A 49-year-old female with primary hyperparathyroidism who initially early 2018 via traditional open approach (Fig. 1). underwent a minimally invasive parathyroidectomy which was Her past medical history included hypertension and she was converted to an open parathyroidectomy after large multilobulated an active cigarette smoker. She had no previous neck surgery but descended right parathyroid adenoma was identified and was had a laparoscopic hysterectomy 6 months prior. technically not able to be removed through a keyhole incision. An At operation, a parathyroid adenoma was not easily identifiable enlarged left superior gland was also identified and resected. Both and 660 mg of fibrofatty tissue with a right inferior parathyroid inferior glands were unable to be located, presumably lying deep adenoma embedded within was resected. After further exploration within the thymus. She tolerated the procedure without issue but a left inferior parathyroid gland was not identified and paratracheal post operatively developed significant chest pain with a chest X-ray tissue on the left was resected along the course of the RLN and showing bilateral apical pneumothoraxes which were managed the left thymus was resected. A right hemithyroidectomy was conservatively and the patient was discharged home without any then performed without difficulty. The right RLN and EBSLN ongoing concern. were identified and preserved and function confirmed with a No VM was performed but intraoperatively the patient neuromonitor. developed laryngeal spasm and the laryngeal mask was changed Prior to skin closure a VM was performed as per the surgeon’s to an endotracheal tube. usual protocol of 40 mm Hg for 30 seconds. Whilst normal saline was in the wound, an air leak was noted coming from behind the Discussion sternum arising from the anterior superior mediastinum, below This case series highlights an unusual complication following the level of surgical dissection. The neck was closed in the usual parathyroidectomy, which has been reported previously on four fashion. patients following minimally invasive parathyoidectomy.3​ The Within an hour post surgically the patient developed pain etiology for this is unclear and it was presumed that VM was in the upper chest and neck and several hours later developed responsible in the first case, but no VM was performed in the other subcutaneous emphysema behind her wound. two cases. The etiology in the most recent case is likely different to Postoperative CXR identified a pneumomediastinum with the previous two cases in this series and what has previously been surgical emphysema without obvious pneumothorax. She was reported in the literature, with a distinction that in the most recent monitored in the high dependency unit for 36 hours and was then case, the patient also developed subcutaneous emphysema (SE) in returned to the ward. The subcutaneous emphysema resolved and the neck which is likely driven by an ongoing air leak, as opposed she was discharged home without ongoing issue. to the earlier two cases which is more likely related to dissection Patient 2 in the upper mediastinum with negative intrathoracic pressures A 74-year-old female with primary hyperparathyroidism who causing air to track downwards into the chest. underwent minimally invasive parathyroidectomy for a large There are multiple etiologies associated with SE, normally as a result of puncture or rupture of part of the respiratory or gastrointestinal system with gas/air being trapped in the subcutaneous tissue.4​ Soft tissue infections with gas forming bacteria are also a potential cause of SE.4​ Cervical SE is most often seen following pneumothorax and with ICC insertion as well as with procedures of the cervical trachea and larynx but cervical SE has even been reported following a case of perforated colonic diverticula.5​ SE has also been reported as a rare complication of thyroidectomy as a result of tracheal injury. Late SE has been associated with tracheal necrosis following thyroidectomy.6​,​7​ Another case report describes a young patient with SE on day nine post thyroidectomy and at reoperation a tracheal tear without necrosis was identified.8​ In the first case the combination of cervical SE and pneumomediastinum, with air bubbling during the VM makes a tracheal injury to be very unlikely as the leak was seen coming from the mediastinum. The two hypotheses that could have led to this Fig. 1: Patient-1 postoperative chest X-ray showing pneumomediastinum combination of pathology is either, an apical bulla that ruptured with cervical subcutaneous emphysema from VM with a direct communication into the neck from upper

World Journal of Endocrine Surgery, Volume 11 Issue 2 (May–August 2019) 47 Pneumothorax and Pneumomediastinum with Subcutaneous Emphysema mediastinal dissection causing injury to the pleura, or it could be been presented in this paper, with the constant risk being cervical due to direct injury of the pleura and apex of the lung itself. In this dissection of the upper mediastinum. second theory, the VM would have only been diagnostic in alerting Valsalva maneuver is a common technique used at the end of the surgeon that this injury would have occurred as opposed to head and neck surgical cases to identify bleeding sites. The rarity being the causal factor. of this complication should not factor in to the decision made by Valsalva maneuver is generally considered a very safe the surgeon as to whether or not to use a VM at the end of the case maneuver, low and colleagues at the Mayo Clinic have performed for bleeding site identification. 4,000 awake VM’s a year since 1993 and have reported no Valsalva maneuver has utility in diagnosing this complication complications.2​ The literature though does report multiple intraoperatively. Bubbling during VM can alert the astute surgeon cases of rare complications related to VM, with cases of Valsalva of this complication and should trigger a management algorithm retinopathy, hyphema, pneumomediastinum and pneumothorax including use of a drain in the neck wound and post-operative CXR being some.2 ​If VM was the cause of the subcutaneous emphysema, with the appropriate management of pneumothorax. this iatrogenic injury could have been avoided by not performing this technique. References It is also important to assess the efficacy of VM for hemostasis. 1. Chang L, Neill CO, et al. Sutureless total thyroidectomy: a safe A 2010 Cambridge study “Hemostasis in head and neck surgical and cost-effective alternative. ANZ J Surg 2011;81:510–514. DOI: procedures: Valsalva manoeuvre vs Trendelenburg tilt” compared 10.1111/j.1445-2197.2010.05492.x. these two techniques in detecting bleeding points to achieve 2. Kumar CM. Intraoperative Valsalva maneuver: a narrative review adequate hemostasis. Trendelenburg tilt was defined as 30 degrees ratoire: une revue narrative Manœuvre de Valsalva perope. Can J head down tilt and was carried out for a median of 6 minutes Anesth 2018;65:578–585. DOI: 10.1007/s12630-018-1074-6. compared to VM which was carried out for a median of 30 seconds 3. Guerrero MA, Wray CJ, et al. Minimally Invasive Parathyroidectomy at 30 cm PEEP. A total of 50 patients were enrolled in this study Complicated by Pneumothoraces: A Report of 4 Cases. J Surg Educ 2007;64(2):101–107. DOI: 10.1016/j.jsurg.2006.10.006. and majority of operations were hemi/total thyroidectomy. “The 4. Vilaça AF, Reis AM, et al. The anatomical compartments and their Trendelenburg technique proved more sensitive in identifying connections as demonstrated by ectopic air. Insights Imaging bleeding vessels that were not seen by Valsalva (113/134 bleeding 2013;4(6):759–772. DOI: 10.1007/s13244-013-0278-0. vessels identified). It is worth noting that, in five cases, significant 5. Fleischer BP, Carney MJ, et al. Perforated colonic diverticula bleeding that required stitching or tying was missed using VM.” presenting as periorbital and cervical subcutaneous emphysema. The authors concluded that Trendelenburg tilt was superior to VM Am Surg 2017;83(6):677–678. and their institution now only performs 30 degree head down tilt 6. To EW, Tsang WM, et al. Tracheal necrosis and surgical emphysema: without the use of VM.9​ A rare complication of thyroidectomy. Ear Nose Throat J 2002;81(10): 738–741. DOI: 10.1177/014556130208101016. 7. Alevizos L, Tsamis D, et al. Delayed tracheal rupture after Conclusion thyroidectomy. Am Surg 2012;78(4):E227–E228. This paper reports a rare complication of parathyroidectomy. The 8. Mazeh H, Suwanabol PA, et al. Late manifestation of tracheal rupture after thyroidectomy: case report and literature review. Endocr Pract initial concern prior to writing this paper was that VM was implicated 2012;18(4):e73–e76. DOI: 10.4158/EP11344.CR. in causing a pneumothorax. From this case series it is shown to 9. Moumoulidis I, Pero MMD, et al. Haemostasis in head and neck be extremely uncommon with only one case in 15,000 cases in surgical procedures: Valsalva manoeuvre vs Trendelenburg tilt. Ann the last 20 years, in which a VM could be implicated. A number R Coll Surg Engl 2010;92(4):292–294. DOI: 10.1308/003588410X1266 of hypotheses as to the causality of this rare complication have 4192076412.

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